Nora and her father have post-traumatic stress disorder (PTSD), triggered by their shared experience of a mass shooting that killed her mother. PTSD influences Nora’s outlook on life and her feelings about herself. Learning more about this psychiatric disorder can provide a deeper understanding of Nora’s character and greater empathy in general for those who have PTSD.

PTSD can result from any traumatic event—experiencing a natural disaster; being in a car accident; being a victim of violence, abuse, bullying, or sexual assault; seeing someone hurt or killed; or losing a friend or family member to violence. People who witness or experience such an event initially have trouble coping with their feelings but usually get better over time. If their symptoms worsen, last for a long time, or interfere with their daily lives, they likely have PTSD.

Though once considered primarily a disorder affecting military or combat veterans, PTSD can affect anyone of any age who has had a traumatic experience. According to the American Psychiatric Association (APA), PTSD affects 3.5% of adults in the US, and the APA estimates that one in 11 people will be diagnosed with PTSD in their lifetime (“What Is Posttraumatic Stress Disorder (PTSD)?” American Psychiatric Association, Nov.